Recently, new techniques have been commercialized to provide equipment health monitoring and early warning of equipment failure. Unlike prior techniques that depend on a precise physical understanding of the mechanics of the machine's design, these new techniques rely on empirical modeling methods to “learn” normal equipment behavior so as to detect nascent signs of abnormal behavior when monitoring an ailing machine or process. More specifically, such new techniques learn operational dynamics of equipment from sensor data on that equipment, and build this learning into a predictive model. The predictive model is a software representation of the equipment's performance, and is used to generate estimates of equipment behavior in real time. Comparison of the prediction to the actual ongoing measured sensor signals provides for detection of anomalies.
According to one of the new techniques described in U.S. Pat. No. 5,764,509 to Wegerich et al., sensor data from equipment to be monitored is accumulated and used to train an empirical model of the equipment. The training includes determining a matrix of learned observations of sets of sensor values inclusive of sensor minimums and maximums. The model is then used online to monitor equipment health, by generating estimates of sensor signals in response to measurement of actual sensor signals from the equipment. The actual measured values and the estimated values are differenced to produce residuals. The residuals can be tested using a statistical hypothesis test to determine with great sensitivity when the residuals become anomalous, indicative of incipient equipment failure.
While the empirical model techniques have proven to be more sensitive and more robust than traditional physics-based models, allowing even for personalized models specific to individual machines, the development and deployment of the equipment models represents significant effort. Empirical models are not amenable to a complete and thorough elucidation of their function, and so creating properly functioning models is prone to some trial and error. Furthermore, since they are largely data-driven, they can only provide as much efficacy for equipment health monitoring as the data allows. It is often difficult to know ahead of time how well a data-derived model will be able to detect insipient equipment health problems, but it is also unreasonable to await a real equipment failure to see the efficacy of the model. Tuning of an empirical model is also more a matter of art than science. Again, because the model is derived from data, the tuning needs of the model are heavily dependent on the quality of the data vis-à-vis the equipment's dynamic range and the manner in which the equipment can fail. Currently, model-based monitoring systems require significant manual investment in model development for the reasons stated above.
There is a need for means to better automate the empirical modeling process for equipment health monitoring solutions, and to improve the rate of successful model development. What is needed is a means of determining the capabilities of a given data-derived model, and of comparing alternative models. What is further needed is a way of automating deployment of individual data-derived models for fleets of similar equipment without significant human intervention. Furthermore, a means is needed of tuning a model in-line whenever it is adapted without human intervention.